Implementation Of Nature-based Solutions Research Articles

Seven Years of Monitoring the Development of an Oyster Reef Living Shoreline

The implementation of nature-based solutions (NbS), including living shorelines, to mitigate estuarine habitat loss is increasing at a pace exceeding the evaluation of their long-term success. Constructed oyster reefs (CORs) made of shell, concrete, stone, and other materials are one living shoreline tactic that is widely utilized, yet few studies have been conducted to understand the development of CORs within the context of both physical and ecological parameters over longer time scales (4 + years). A COR-based living shoreline project at the Gandy’s Beach Preserve (GBP) in Delaware Bay, NJ, USA, had dual goals of coastal protection and habitat provisioning, which prompted the development of a goal-driven monitoring framework to track project objectives. Methods were developed to quantify the following multi-disciplinary metrics over 7 years: elevations of CORs, waves (height, period, and direction), shoreline elevations, change in extent of vegetation patches, oyster density and size, nekton richness and community composition, and horseshoe crab impingement. The CORs met most of their habitat provisioning objectives as they were colonized by a multi-generational population of shellfish and created habitat for nekton, while posing negligible hazards to horseshoe crabs. However, none of the coastal protection objectives was fully achieved including material stability, wave attenuation, and sediment elevation increase. Results highlight the value of longer-term monitoring to understand performance and the need to match the scale and type of NbS tactic(s) with both the scale of the landscape and the site-specific hydrodynamic conditions to meet project goals.

Evaluating the impact of Nature-based Solutions on the provision of water-related and water-dependant Ecosystem Services

Water scarcity is a pressing issue in the Mediterranean region, exacerbated by overuse of resources for agriculture and the impacts of climate change. Addressing this challenge requires improved water cycle management and the adoption of Nature-based Solutions (NbS) to enhance infrastructure efficiency and sustainability. With the aim of promoting the implementation and assessment of NbS, we have developed a monitoring framework that integrates the assessment of ecological, socio-economic and cultural aspects under the umbrella of the IUCN Global Standard for NbS. A list of Key Performance Indicators (KPIs) was selected following standard methodologies. We have applied the framework to five case studies in the Mediterranean region to evaluate its efficiency to assess NbS tailored to local challenges and contexts. As part of the monitoring framework, we used the IUCN self-assessment tool for the Global Standard for NbS, demonstrating adherence of 50-75% across all case studies. Common KPIs were identified, streamlining monitoring efforts and providing guidance from the design phase onwards. Our monitoring framework offers a comprehensive approach to evaluating NbS interventions, ensuring alignment with global standards and enhancing resilience in water management. By integrating the IUCN Global Standard, it provides robust guidance for future execution, contributing to sustainable water resource management in the Mediterranean and beyond.

The plant ecology of nature‐based solutions for people, biodiversity and climate

Abstract Integrated solutions to the climate and biodiversity crises—together with other global sustainability challenges—include the identification, design and implementation of nature‐based solutions (NbS). Living organisms mediate biogeochemical cycles and greenhouse gas fluxes from land and sea, and provide NbS to both climate change mitigation and adaptation. Plants, as the primary producers in ecosystems, lie at the heart of NbS. Plant ecology provides the foundation for developing and evaluating NbS based on an understanding of the ecological processes that underlie ecosystem service flow to people. In this Special Feature, we provide a collection of mini‐reviews that presents concise and focused analysis of the plant ecology of NbS. The mini‐reviews highlight key insights, challenges and opportunities for future research. The development of NbS that target specific ecosystem functions (e.g. carbon storage), or aim at increasing ecosystem resilience against perturbations (e.g. those associated with climate change), requires unification of ecological theory from areas such as biodiversity‐ecosystem function, plant–animal interactions, resilience and functional traits of organisms. Synthesis. Plant ecology and nature‐based solutions (NbS) research are complementary. Plant ecology can inform the design and management of effective NbS, and provide insights for the creation of novel ecosystems that provide NbS; while learning from the implementation of NbS can progress theory. To deploy NbS at the speed and scale needed to mitigate and adapt to climate change, we must rapidly integrate ecological concepts into the design of NbS. At the same time, the design and deployment of NbS in different ecological contexts provides an unprecedented opportunity to learn how performances of individual NbS sites can be explained in an integrated way, leading to the development of general concepts. Ultimately, a mechanistic understanding of how plants and their functional traits contribute to ecosystem function and service provision is critical for the design, verification of benefits from and avoidance of adverse effects of NbS.

Policies and practices impacting the implementation of nature-based solutions: a comparative study of ponds and pondscapes in eight countries

Nature-based solutions (NBS) are increasingly suggested to address biodiversity decline and climate change. However, many ecosystems are hardly used as NBS, including ponds and pondscapes. We therefore examine how policies and practices affect their implementation as NBS. Using a content analysis of policy documents and stakeholder inputs, we assess the policy context in eight countries but also zoom in on policies and practices in seventeen pondscapes. We derive three key insights: first, a protective status for a pond or pondscape interlinks with other enabling factors for NBS implementation, and protection and conservation should therefore be considered more often as NBS. Second, there is a shortage of, especially long-term, financing. Third, local leadership should be nurtured to overcome a lack of institutional cooperation and stakeholder awareness as well as fragmented land ownership. Beyond that, we show that implementation barriers interlink and interventions should therefore address several barriers simultaneously.

Assessment of nature-based solutions for water resource management in agricultural environments: a stakeholders' perspective in Southern Italy.

This paper explores the potential implementation of Nature-Based Solutions (NBSs) in agriculture, specifically focusing on soil and water management in Southern Italy, particularly in the Apulia and Basilicata regions. Through a tailored questionnaire, it investigates farmers' perceptions of the utility of NBSs, addressing key issues in the region and evaluating their role in addressing soil and water management challenges. Findings reveal primary challenges such as drought, floods, and water pollution, with soil erosion being a major concern. Several NBSs, including wetlands and bioswales, demonstrate consistent utility and performance, while disparities exist for agroforestry and strip cropping. The study underscores a significant gap in the economic valuation of NBSs, emphasizing the need for comprehensive assessments that incorporate livability improvements, water quality enhancement, and socio-cultural benefits. Additionally, an analysis of NBS implementation across Italian agriculture reveals limited case studies, suggesting the need for strategic expansions to meet Sustainable Development Goals. This research offers critical insights into the effectiveness and challenges of NBSs in agricultural soil and water management, advocating for enhanced stakeholder engagement and the development of multidimensional evaluation frameworks to support sustainable practices.

Implementation of Nature-Based Solutions in Urban Water Management in Viet Nam, a Comparison among European and Asian Countries

Climate change is severely affecting all regions of the world, and urban water management has become a major urban challenge. Although nature-based solutions (NBSs) have been widely implemented in developed countries in the Global North to address stormwater-related challenges in urban areas, implementation of such approaches in Viet Nam and other Asian countries remains limited. In addition, comprehensive and critical reviews of NBS adoption and development processes in Viet Nam are scarce. This study aims to clarify several aspects through a literature-based review: to understand the development of urban water management in Europe and Asia (China and Southeast Asian countries) along with the drivers for NBS implementation in Viet Nam, to explain the barriers to NBS adoption in Viet Nam, to present feasible solutions for promoting NBS adoption, and to explore future perspectives for NBS development in the context of Viet Nam. Although significant barriers exist, opportunities for NBS implementation are evident. The findings of this study can be used to promote NBS in other municipalities in developing countries.

Selection, Planning, and Modelling of Nature-Based Solutions for Flood Mitigation

The use of nature-based solutions (NBSs) for hazard mitigation is increasing. In this study, we review the use of NBSs for flood mitigation using a strengths, weaknesses, opportunities, and threats (SWOT) analysis framework for commonly used NBSs. Approaches reviewed include retention and detention systems, bioretention systems, landcover and soil management, river naturalisation and floodplain management, and constructed and natural wetlands. Existing tools for identification and quantification of direct benefits and co-benefits of NBSs are then reviewed. Finally, approaches to the modelling of NBSs are discussed, including the type of model and model parameterisation. After outlining knowledge gaps within the current literature and research, a roadmap for development, modelling, and implementation of NBSs is presented.

Leveraging Greenspace to Manage Urban Flooding: An Investigation of Nature-Based Solutions Implementation in U.S. Public Parks

Many cities are looking to adopt nature-based solutions (NBS) in greenspace to manage urban flooding and provide diverse co-benefits. Yet little research exists to inform the planning and design of park NBS. This study investigated NBS adoption in 58 public parks across major U.S. cities, using a 2022 survey by the Trust for Public Lands and other secondary datasets. We developed a typology to conceptualize a wide range of park NBS into five high-level categories by size/capacity, location of the gray–green spectrum, and design objectives. We then employed this typology to explore how a park’s adopted NBS types may relate to its landscape and sociodemographic contexts. We found that the most used type of NBS in the studied parks was ECO (a typology we defined as conserving, restoring, or creating ecosystems to mitigate flooding through ecological processes and functions), while the least used NBS type was ENG (a typology we defined as imitating natural infiltration processes but having no living elements). Further, parks that adopted ECO had significantly higher percentages of greenspace in the surrounding, as well as higher flood risks. We also found notable—though not statistically significant—evidence of potential associations between the type of NBS implementation in a park and its nearby neighborhoods’ income level, poverty, and population racial and age compositions. Moreover, our findings indicated that park visitors were more privileged compared to residents living near a park. We concluded that park contextual factors deserve more explicit consideration in the planning and design of NBS and discussed key implications of this study for practice and future research around park NBS for urban flooding.

Nature-based solutions across spatial urban scales: three cases studies from Nice, Utrecht and Milan

A holistic vision for urban sustainability looks at the city as an integration of energy, environment, mobility, urban design, new technologies and, most importantly, ‘people and nature’. In this article, the aim is to shed light on the role of nature-based solutions (NBS) towards addressing climate change crisis and tackling a variety of socio-ecological and urban biodiversity challenges. The paper claims for more evidence-based frameworks to understand the economic, social and environmental benefits of NBS and to promote their inclusion in urban policies. First, and most importantly, the role of NBS in shaping urban planning as a result of expansion and densification of cities is reviewed. Second, the co-benefits generated by NBS within the social and cultural regeneration of cities are reflected upon. Lastly, case studies are given from Nice, Utrecht and Milan in order to showcase those cities’ spatial strategies to implement NBS through different scales. The article discusses the role of NBS in addressing climate challenges and emphasises the need for collaborative stakeholder engagement in their implementation. Spatial, governance and temporal challenges related to NBS implementation are identified, underscoring the complexity of integrating NBS into urban environments. The article concludes by advocating for systematic integration of green and blue infrastructure and NBS into urban planning, emphasising the importance of considering socio-cultural elements alongside environmental benefits.

Public participation and NGO activity in nature-based solutions in urban areas of China

This paper analyses the degree and types of public participation in Nature-Based Solutions (NBS) projects in China. The paper is based upon the premise that NBS affect multiple aspects of the city as a place for the daily lives and activities of citizens and that NBS implementation can benefit from citizen and stakeholder involvement. NBS thus offer a platform for stimulating engagement between the local government and the public. Case studies are examined through a literature review, site visits, and interviews with researchers, local officials and NGOs in China. The paper indicates that there has been significant progress since the 1990s in formal requirements of public participation through Chinese legislation promoting the inclusiveness of the public in environmental and NBS decision-making, and acknowledgment of the importance of NGOs, however actual implementation of soliciting public opinion and involvement in NBS project design has been more limited. The case studies suggest that the level of involvement of the public in NBS activities and decision-making is the reciprocal of the size of the project, where there is a high-level of involvement in the smaller local projects, but minimal involvement in larger-scale NBS projects. We find that Public Private Partnerships (PPPs) have a significant potential to help finance NBS projects providing the project can forecast low risk and positive revenue for investors, therefore this model would merit further exploration. However, PPPs may also involve limited public participation by citizens and stakeholders beyond private companies and may therefore require targeted efforts to address local communities’ needs and interests. Local people are the most important (and willing) actors and opinionators in projects that directly affect their lives, livelihoods and well-being. The findings highlight the important role of NGOs in promoting and facilitating public participation, and accompanying co-benefits, in several of the Chinese case studies. Our study also suggests that symbiosis between local governments and the citizens could be invoked by local community-based organisations (e.g. Community Resident Committees or similar) that can act as a liaison point and catalyst to public participation in NBS projects, although significant training would also be required.

The role of Nature-Based Solutions for the water flow management in a Mediterranean urban area

Due to climate change and rapid urban sprawl, central Mediterranean regions are subjected to short but intensive storm events resulting in a significant increase of flow rates and runoff volumes in low-lying coastal urban areas. Within the framework of green urban infrastructures (GUIs), a suitable combination of Nature-Based Solutions (NBS) with traditional grey infrastructures should be adopted to mitigate flood risk effects in urban and sub-urban areas contributing at the same time to achieve multiple benefits for both the environment and the community. The aim of this study is (i) to evaluate flood hazard maps for identifying the areas within a Sicilian hydrological river basin (Toscano catchment) with a high risk of flooding by implementing the HEC-RAS model at catchment scale; (ii) to quantify the peak flow and floodplain area reduction; (iii) to assess the effectiveness of small-scale NBS (green roofs, porous pavements, rain gardens and rain barrel), in terms of peak flow and runoff volume reductions, at urban block scale by using the EPA SWMM model Model simulations are performed integrating the hydraulic (HEC-RAS) and hydrological (EPA SWMM) models for return periods of 10, 50 and 200 years. The results showed that the estimated peak flow (m3 s−1) obtained from the simulations performed at catchment scale for each T in the current scenario (without NBS) using HEC-RAS and EPA SWMM models are very close to each other (R2 = 0.99). In addition, the utopian scenario simulation showed the HEC-RAS model sensitivity to CN calibration achieving a peak flow reduction up to about 60% with the floodplain area decreasing up to about 17%. Finally, the model EPA SWMM shows its sensitivity to NBS implementation at urban block scale with a peak flow reduction up to about 16% and a runoff volume (mm) reduction up to about 24%. These reductions decrease as T increases with a higher NBS mitigation effects for the lowest T. The results highlighted that the integration of NBS in urban areas could have hydrological and hydraulic positive effects, particularly in terms of peak flow and runoff volume reduction. Furthermore, the results suggest that small-scale NBS have a potential to be effective to smaller rainfall events, but a combination with large-scale NBS is necessary to cope with extreme events.

Testing the hydrological performance of live pole drains (LPD) for mitigation of slope instability

Nature-based solutions (NbS) and soil bioengineering techniques have gained considerable attention due to their relevant hydrological functions and ability to mitigate slope instability. Live pole drains (LPD), a lesser-known NbS, have traditionally been deployed on slopes to drain the excess surface water and regulate the soil's water budget, making it a suitable technique for stormwater management and landslide prevention. However, neither the LPD performance as a plant-based drainage system nor its potential to regulate the soil-water budget through hydrological processes have been thoroughly studied. This paper presents a novel pilot, lab-based approach for testing the hydrological performance of LPD under different soil hydrological conditions. We built three different treatments and investigated their hydrological performance under multiple storm events. We explored how LPD regulate the soil-water budget by partitioning the water inputs (i.e., rainfall precipitation) into water outputs (i.e., surface runoff, subsurface flow, and percolation). The study revealed that LPD can effectively manage stormwater by draining excess runoff and buffering water in the soil, outperforming fallow soil. Subsurface flow and percolation were significantly higher under LPD treatments when compared to fallow ground, suggesting that the presence of an enhanced structure in the soil results in high soil hydrological performance. The presence of a secondary species with the LPD showed a more efficient hydrological performance than an LPD alone, which aligns with the current implementation of NbS fostering biodiversity. Antecedent soil moisture impacted the hydrological performance of LPD by altering the relative infiltration capacity of the soil and by potentially modifying the availability of channels for preferential flow. Our findings provide a sound basis for future research to improve our understanding of the hydrological performance of LPD for slope instability mitigation and encourage their reproduction and upscaling.

Moving Towards a Holistic Approach to Circular Cities: Obstacles and Perspectives for Implementation of Nature-Based Solutions in Europe

Nature-based solutions (NBS) are frequently implemented without taking the system’s perspective into account and with the main focus on technical and economic issues of implementation. This study was conducted to test the hypothesis on the potential synergistic effects between circularity and NBS to holistically tackle urban challenges. The main objective is to establish preliminary insights on the obstacles and perspectives of NBS integration and implementation, through a questionnaire set up by the network of experts gathered within the COST Action CA17133 Circular City. The following research questions arise: (i) what differences exist in the level of NBS application according to the variance of engaged countries; and (ii) what are the main obstacles and perspectives for the NBS implementation in order to holistically tackle urban challenges, enhancing the sustainable connection among urban environment, nature, and human well-being. To go beyond the current state-of-the-art and reflect on the research conducted within the Circular City Action, this study aims to open a multi-geographical academic dialogue across Europe and beyond and to move towards a holistic approach to circular cities. Accordingly, this study is: (1) multi-geographical and context-based, providing input for thirty-three EU countries and four non-EU countries to give an overview of the main obstacles and perspectives of NBS implementation, and (2) approach-directed, aiming to formulate a holistic approach to deal with societal challenges. This document intends to provide qualitative and quantitative insight into the potentials and obstacles of NBS implementation in Europe, as well as to motivate further discussion and research to achieve holistic and sustainable cities.

Monitoring and assessment in the context of governance of nature-based solutions. Shared challenges and opportunities in CELAC and EU cities

The concept of Nature-based Solutions (NbS) has gained interest as an approach to make significant contributions to the transformation towards more liveable, sustainable, and climate-resilient cities. However, the uptake of NbS into urban development practice is hindered by knowledge and governance barriers. Knowledge plays an essential role in evidence-based decision-making processes and in building the capacity to co-design sustainable pathways. In turn, governance processes can greatly support the acquisition, dissemination and application of knowledge. However, little is known about how these interactions between governance and knowledge manifest in practice. Therefore, we aim to understand the interplay between governance and monitoring & assessment (M&A) and the associated challenges and opportunities for NbS implementation in European and Latin American cities. Considering different socio-economic and cultural contexts allows us to draw from a wider range of practitioners’ experiences in different governance settings. We conducted an explorative qualitative content analysis on ten semi-structured expert interviews with thirteen city experts from local governments and academia based in seven cities: Bogota (CO), Buenos Aires (AR), Santiago (CL), São Paulo (BR), Barcelona (ES), Lisbon (PT) and Turin (IT). Our findings show that M&A provides agency for individual, institutional actors to steer political commitment and can support integrated working. The potential of collaborative M&A with non-governmental actors is still largely untapped, which requires acknowledgement of the capacities of non-governmental actors to contribute to M&A and raise awareness of the value of M&A to civil society. Furthermore, we recommend integrating more reflective learning opportunities in M&A processes, paying more attention to data sharing, and considering of more feasible M&A processes.

Transforming ambition into action to catalyse nature-based solutions: Insights from 250 good practice policy instruments

Ambition to leverage the power of nature-based solutions (NbS) to address global challenges such as the interlinked climate change and biodiversity crises has reached unprecedented levels. Despite a growing consensus around the potential benefits of NbS, this ambition has not translated into sufficient actionable progress in practice. Cities, increasingly recognized as centres of transformative capacity, have become a focal point for achieving NbS ambitions. Nevertheless, the transition from theoretical discourse to practical implementation has been slow, with NbS frequently being overlooked until recently in political agendas. A key obstacle to progress is the lack of action-oriented research grounding theoretical discussions in empirical evidence on NbS policy design and application. This paper seeks to address these knowledge gaps by: (i) defining criteria for good practices in urban NbS policy design and implementation; (ii) assessing policy instruments from the Urban Governance Atlas (UGA) against these criteria using mixed statistical and qualitative methods; and (iii) identifying potential pathways and actionable measures to promote the adoption of good practices in practice. Drawing on the diverse UGA examples, with a particular focus on Europe and the CELAC region, the paper identifies seven good practice criteria and outlines four potential pathways and related actions to guide the development of NbS policy instruments across varied urban contexts. Concrete recommendations around actionable knowledge aim to tap the transformative potential of NbS in addressing pressing global issues.

Spatial and Temporal Variability in Bioswale Infiltration Rate Observed during Full-Scale Infiltration Tests: Case Study in Riga Latvia

Urban nature-based solutions (NBSs) are widely implemented to collect, store, and infiltrate stormwater. This study addressed infiltration rate as a measure of the performance of bioretention solutions. Quick scan research was conducted, starting with mapping over 25 locations of implemented green infrastructure in Riga, Latvia. Basic information, such as location, characteristics, as well as photos and videos, has been uploaded to the open-source database ClimateScan. From this, eight bioswales installed in the period 2017–2022 were selected for hydraulic testing, measuring the infiltration capacity of bio-retention solutions. The results show a high temporal and spatial variation of infiltration rate for the bioswales, even those developed with similar designs: 0.1 to 7.7 m/d, mean 2.0 m/d, coefficient of variation 1.0. The infiltration capacity decreased after saturation: a 30% to 58% decrease in infiltration rate after refilling storage volume. The variation in infiltration rate as well as infiltration rate decrease on saturation is similar to other full-scale studies done internationally. The infiltration rate of most bioswales falls within the range specified by international guidelines, all swales empty within 48 h. Most bioswales empty several times within one day, questioning the effectiveness of water retention and water availability for dry periods. The results are of importance for stakeholders involved in the implementation of NBS and will be used to set up Latvian guidelines for design, construction, and maintenance.

Unravelling stakeholder narratives on nature-based solutions for hydro-meteorological risk reduction

Despite growing scholarly consensus on the need for nature-based solutions (NBS) as holistic and sustainable alternatives to traditional engineering solutions, stakeholder acceptance and implementation of NBS remain low. This study investigates stakeholder narratives on implementing nature-based solutions (NBS) for mitigating hydro-meteorological risks across five European river basin sites in Eastern and Central Europe. Utilising the Q-methodology and narrative analysis, we identified three ideal–typical narratives: idealist, reformist, and sceptic—each providing distinct perspectives on evidence-based policy formation and NBS integration. Our results demonstrate that: (1) idealists’ optimistic outlook risks overlooking critical engagement with implementation challenges; (2) neglecting sceptic concerns may impede NBS adoption and invite accusations of green-washing, and (3) reformists promote evidence-based approaches and transparent stakeholder engagement to bridge narrative divides. The study underscores the importance of identifying shared values, stakeholder collaboration, and a nuanced understanding of contextual factors in fostering NBS implementation. The study contributes to a practical framework aligning NBS projects with prevailing narratives, offering guidance for navigating the complex landscape of NBS implementation. Future research should prioritize in-depth analysis of agent perspectives, place-specific influences on narratives, and the application of narrative analysis to other emerging technologies and environmental topics (e.g. circular economy), deepening our understanding of the socio-political dynamics shaping the acceptance and implementation of sustainable solutions.

Exploring Apulia’s Regional Tourism Attractiveness through the Lens of Sustainability: A Machine Learning Approach and Counterfactual Explainability Process

Visitor attraction dynamics lead tourism industry paths. A complex artificial neural network model was built to predict the incoming tourism flow in the Apulia region of Southern Italy as a function of the heterogeneity of the tourism supply available in this area. Open data from the Regional Tourism Observatory were targeted. Information on the distribution of facilities and activities that attract regional tourist flows was collected and grouped by municipality. An artificial neural network model was built with total tourist attendance as the dependent variable and tourist attractions as regressors. The Root Mean Square Error (RMSE) was used to select the optimal model using the lowest value. The final model was run with a hidden layer consisting of three neurons and a decay value of 0.01. A Multi-Objective Counterfactual model (MOC) was then constructed using a randomly selected row of normalized data frame to validate a useful tool in increasing total tourist attendance by 20% over that of the randomly selected municipality. A Garson’s variables importance plot indicated natural landscapes such as beaches, sea caves, and natural parks have a primary role expressed in terms of variable importance in the AI algorithm when used as an innovative methodology for evaluating tourism flows in the Apulia region. A further MOC model built using a randomly selected row of normalized data frame showed convents, libraries, historical buildings, public gardens, and museums as the top five features most modified to improve total attendance in a randomly selected municipality. Use of AI modeling revealed that the implementation of nature-based solutions may speed up the flow of tourism in the Apulia region while also promoting sustainable social development.

Multidimensional assessment of a Nature-based Solution for decentralized greywater treatment in Costa Rica

In Costa Rica, water supply networks provide water to over 94% of the country's population. However, only an estimated 14% of wastewater receives proper treatment. The lack of centralized sanitation infrastructure has resulted in the use of septic tanks and the discharge of untreated greywater into rivers, causing environmental degradation of surface waters. Retrofitting conventional centralized sewer networks and treatment plants into the existing urbanization presents extensive social, economic, and technical challenges. Nature-based Solutions (NbS) for greywater treatment can reduce pollutant loads and improve the environmental status of water resources and represent an opportunity for technical leapfrogging towards sustainable, decentralized on-site treatment and reuse. However, the implementation of NbS in urban areas poses significant challenges due to the complex interplay of social, regulatory, and economic factors. Specifically, for on-site greywater treatment systems, meeting several criteria, including efficient pollutant removal, affordability, and public acceptance is essential for successful implementation and operation. This study assesses the technical, socio-economic, and political-regulatory dimensions relevant to implementing NbS for decentralized greywater treatment. To conduct this research, a Real-World Lab was established in the Great Metropolitan Area of Costa Rica, employing a transdisciplinary approach. This approach provided a physical space and societal context to integrate site-specific aspects and understand the various factors that influence the implementation and upscaling of NbS. As part of our methodology, we analyzed the water quality parameters and treatment performance of a NbS prototype for decentralized greywater treatment. Within the Real-World Lab framework, we conducted interviews, surveys, and field observations to investigate socio-economic and political-regulatory aspects. Our results highlight the technical potential of the NbS prototype. However, the limitation lies in the governance scheme and financing mechanisms required for upscaling the NbS as a decentralized on-site technology across the country. Our multidimensional assessment provides insights into the requirements for widespread implementation of NbS, applicable to other regions facing similar retrofitting sanitation challenges.

Community-engaged flood mitigation and ecological restoration on a university campus

Abstract Urban flooding is a major climate change risk that can be mitigated with green infrastructure such as tree plantings and restored naturalised buffers along watercourses. The creation and maintenance of green infrastructure projects for climate change adaptation provides opportunities for community partnerships and programming with co-benefits for human well-being and biodiversity. Here we present findings of action research on a flooding adaptation and education that was implemented on an urban higher education institution’s campus in partnerships within the university and with local Indigenous peoples, the regional conservation authority, the municipal government, and the public library. Through participatory workshops, we applied bioengineering and mixed planting methods to restore a creek bank. Using a combination of oral storytelling, digital media, and visual art that integrated perspectives across disciplines and knowledge systems, we situated our creek restoration project within a framework of environmental justice, emphasising specific acts of stewardship to improve watershed health and advance reconciliation. We produced digital resources and outreach materials to disseminate lessons from the project into the community and to support similar flooding adaptation efforts at local and global scales. Our project demonstrates how incorporating partnerships into the design and implementation of nature-based solutions can build cross-cultural ecological knowledge, forge important on and off-campus relationships, and create place-based opportunities for students to take direct and measurable action on climate change.